Sal (Shorea robusta) is a wind-pollinated, hermaphrodite tropical forest tree species in South Asia that has suffered significant habitat loss. Despite its economical and ecological importance in the region, so far, no information about its population genetics is available. Using four highly variable nuclear microsatellites, we compared the genetic diversity between adults and juveniles in a semi-isolated natural population in Nepal, quantified its micro-spatial genetic structure by spatial autocorrelation and assessed its pollen and seed flow. Results showed that genetic diversity (HE=0.68, NA=11) was within the range found in other members of the genus. Spatial aggregation of related individuals was weak both in juveniles and adults trees. Selfing rate was 6%, and mean pollen and seed dispersal distances were 194 m and 35 m respectively. The effective neighbourhood size was estimated to be 4,153 trees. The spatial genetic structure and gene flow data presented here can serve as guidelines for conservation and sustainable use of genetic resources of this tropical species.